CN1307816C - DMT system for reducing far end crosstalk - Google Patents
DMT system for reducing far end crosstalk Download PDFInfo
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- CN1307816C CN1307816C CNB028095405A CN02809540A CN1307816C CN 1307816 C CN1307816 C CN 1307816C CN B028095405 A CNB028095405 A CN B028095405A CN 02809540 A CN02809540 A CN 02809540A CN 1307816 C CN1307816 C CN 1307816C
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/02—Channels characterised by the type of signal
- H04L5/06—Channels characterised by the type of signal the signals being represented by different frequencies
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/32—Reducing cross-talk, e.g. by compensating
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2626—Arrangements specific to the transmitter only
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2697—Multicarrier modulation systems in combination with other modulation techniques
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
- H04L2025/03375—Passband transmission
- H04L2025/03414—Multicarrier
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/03433—Arrangements for removing intersymbol interference characterised by equaliser structure
- H04L2025/03439—Fixed structures
- H04L2025/03445—Time domain
- H04L2025/03471—Tapped delay lines
- H04L2025/03484—Tapped delay lines time-recursive
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- Computer Networks & Wireless Communication (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Disclosed is a DMT (discrete multi-tone) system including a first ONU (optical network unit) receiver connected to a first transmission line from a remote site transmitter, and a second ONU receiver connected to a second transmission line, for receiving data signals to which FEXT (far and crosstalk) from the first transmission line is combined. The first ONU receiver comprises: a first equalizer for compensating transmission line attenuation in the data signals received through the first transmission line; and a first slicer for performing decision-making on the output of the first equalizer to find a decision value, and the second ONU receiver comprises: a second equalizer for using a tap coefficient to compensate transmission line attenuation in the data signals to which the FEXT is combined; and an FEXT canceller for using a tap coefficient of the FEXT canceller and a decision value of the first ONU receiver to calculate the influence caused by the FEXT.
Description
Technical field
The present invention relates to the DMT system of crosstalking that a kind of elimination produces in DMT (discrete multi-tone, Discrete Multitone) system.More specifically, the present invention relates to the DMT system of a kind of elimination FEXT (far end crosstalk, far-end cross talk).
Background technology
The demand of supplying by the multimedia service of communication network is increased recently, and developed and used the traditional copper telephone cable that does not have amplifier and repeater that xDSL (the digital subscriber line of the data rate from hundreds of kbps to tens of Mbps is provided, Digital Subscriber Line) method is to satisfy this needs.
XDSL is developed into HDSL (high-data-rate DSL, high data rate DSL), SDSL (single-line HDSL, single line HDSL), ADSL (asymmetric DSL, Asymmetrical Digital Subscriber Line), UADSL (universal ADSL, general ADSL) and VDSL (very-high-bit-rate DSL, very high bit rate DSL) in 300 to 1500m short scopes, to carry out rapid data transmission.
The modulation-demo-demodulation method of xDSL comprises: use SCM (single-carrier modulation respectively, single-carrier modulated) CAP of method (carrierless AM/PM, carrierfree AM/PM) method and QAM (quadratureamplitude modulation, quadrature amplitude modulation) method; With the DMT method of using MCM (multi-carrier modulation, multi-carrier modulation) method.
The DMT method is divided into a plurality of narrow-band subchannels with whole transmission band, and transmits them, thereby increases the transmission cycle of each subchannel according to the number of subchannel, and by simple single tap equalizers compensate for channel distortions.In addition, by adding as protection Cyclic Prefix at interval to DMT code element (symbol), described method keeps quadrature between each subchannel, and removes the interference between the code element, thereby provides simple equalizer configuration in receiver side.And described method uses IFFT (inverse fastFourier transform, invert fast fourier transformation) and FFT (fast Fourier transform, fast fourier transform) can realize High Speed Modulation and demodulation process.
The principal element of decay high data rate comprises in the xDSL system environments: transmission-line attenuation, and by described transmission-line attenuation, signal is propagated and is attenuated because of various factors along transmission line; With crosstalk, as the NEXT (near end crosstalk, near-end cross) that takes place between the approaching transmission line, with FEXT (farend crosstalk, far-end cross talk).
Because the electromagnetic interaction between the UTP (unshielded twisted pair, unshielded twisted pair) in the same cable is crosstalked when the different electrical signals of various transmitter transmission far away influences each other.NEXT is at ONU (optical network unit, optical network unit) influence that forms from the signal of transmitter transmission in the same section (section) of the same side of one of transmission unit and far-end transmission unit, and FEXT is the influence that the signal from the transmitter transmission of opposition side forms.
In the middle of them, the decay that transmission line causes is compensated by equalizer.NEXT reduces systematic function significantly when up link is used identical frequency range with down link signal, therefore, by using D to use the FDD (frequency division duplex, Frequency Division Duplexing (FDD)) of different frequency bands can remove NEXT fully respectively to up link and down link signal.
About eliminating the technology of FEXT, proposed to be applied to the method for single carrier system, still, because the complexity of multicarrier system, do not propose to be applied to the FEXT removing method of multicarrier system as yet.
Summary of the invention
Advantage of the present invention is to eliminate the FEXT (far end crosstalk, far-end cross talk) that produces from adjacent lines in the DMT system, to improve systematic function.
The systematic function that the FEXT that produced by adjacent lines when improving each signal at distant transmitter by channel has reduced provides a kind of technical method that is used to provide the technical method of FEXT arrester and more effectively eliminates FEXT.
In one aspect of the invention, a kind of DMT system comprises the ONU receiver that is connected to from first transmission line of distant transmitter, be used to receive the data-signal that combines from the FEXT of at least one second transmission line, wherein said ONU receiver comprises: equalizer is used for using the transmission-line attenuation of the tap coefficient compensation of described equalizer at the data-signal that combines FEXT; With the FEXT arrester, be used to use the decision content of the tap coefficient of described FEXT arrester and the data by described second transmission line to calculate the influence that FEXT causes, and wherein deduct the output of described FEXT arrester to eliminate described FEXT by output from described equalizer.
In the present invention on the other hand, a kind of DMT system comprises at least one ONU (optical networkunit, optical network unit) receiver, and it is connected to first transmission line from least one distant transmitter; The 2nd ONU receiver, it is connected to second transmission line different with described first transmission line, be used to receive the data-signal that combines from the FEXT of first transmission line, a wherein said ONU receiver comprises: first equalizer is used for compensating the transmission-line attenuation at the data-signal that receives by first channel; With first amplitude limiter (slicer), be used for the output of described first equalizer is made a determination to find decision content, and described the 2nd ONU receiver comprises: second equalizer is used for using the tap coefficient compensation of described second coefficient to combine the fading channel of the data-signal of FEXT; With the FEXT arrester, be used to use the tap coefficient of described FEXT arrester and a described ONU receiver decision content, calculate the influence that FEXT causes, and eliminate described FEXT by the output that the output from described equalizer cuts described FEXT arrester.
Described the 2nd ONU receiver also comprises second amplitude limiter, is used for that the output from described second equalizer is cut the value that the output of described FEXT arrester obtains and makes a determination to find decision content.
The tap coefficient of described FEXT arrester is by the decision errors of the factor of the convergency factor of determining described FEXT arrester, described the 2nd ONU receiver and the decision content convergence of a described ONU receiver.In detail, upgrade the described tap coefficient of described FEXT arrester continuously by following equation, to converge to predetermined value.
Here FC (n) is the tap coefficient of described FEXT arrester, and β is the factor of determining the convergency factor of described FEXT arrester, E
2(n) be described the 2nd ONU receiver decision errors and
It is the decision content of a described ONU receiver.
The tap coefficient of described second equalizer, by the decision errors of the factor of the convergency factor of determining described second equalizer, described the 2nd ONU receiver and the decision content convergence of described the 2nd ONU receiver.In detail, by the continuous tap coefficient that upgrades described second equalizer of following equation, to converge to predetermined value.
Here EQ (n) is the tap coefficient of described second equalizer, and β ' is the factor of determining the described convergency factor of described second equalizer, E
2(n) be described the 2nd ONU receiver decision errors and
It is the decision content of described the 2nd ONU receiver.
Described the 2nd ONU receiver also comprises the 3rd amplitude limiter, be used for the output of described second equalizer is made a determination to find decision content, and pass through the factor, the decision errors of described second equalizer and the decision content of described the 2nd ONU receiver of the convergency factor of definite described second equalizer, restrain the tap coefficient of described second equalizer.In detail, by the continuous tap coefficient that upgrades described second equalizer of following equation, to converge to predetermined value.
Here, EQ (n) is the tap coefficient of described second equalizer, and β ' is the factor of determining the convergency factor of described second equalizer, E
1(n) be described second equalizer decision errors and
It is the decision content of described the 2nd ONU receiver.
Description of drawings
In this manual in conjunction with and constitute its a part of accompanying drawing the embodiment of the invention be shown, and together explain principle of the present invention with explanation:
Fig. 1 is the DMT system block diagram of the elimination FEXT of first and second preferred embodiments according to the present invention;
Fig. 2 and 3 illustrates the operation principle of the FEXT arrester of first and second preferred embodiments in the DMT system according to the present invention respectively.
Embodiment
In the following detailed description, by carrying out the explanation of the preferred forms that of the present invention China invites the person think, illustrate and illustrate the preferred embodiments of the present invention.Can realize as institute, not depart under the situation of the present invention that the present invention can make amendment aspect obvious at each.Therefore, accompanying drawing and explanation should be regarded as illustrative, are not to limit the present invention.
DMT system below with reference to Fig. 1 explanation elimination FEXT of first and second preferred embodiments according to the present invention.
Fig. 1 is a block diagram of eliminating the DMT system of FEXT according to first and second preferred embodiments of the present invention.
As shown in the figure, described DMT system comprises a plurality of distant transmitters 100 and ONU (optical network unit) receiver 200.Distant transmitter 100 comprises: projection instrument (mapper) 110; Serial-parallel converter 120; IFFT (inverse fast Fourier transformer) 130; Parallel-serial converter 140: and framer (framer) 150.ONU receiver 200 comprises a plurality of receiver 200a, and they are connected respectively to a plurality of transmission lines from distant transmitter 100.Receiver 200a comprises: remove frame device (deframer) 210; Serial-parallel converter 220; FFT (fast fourier transformer) 230; Equalizer 240; FEXT arrester 250; Parallel-serial converter 260; With remove projection instrument (demapper) 270.
Convert the data-signal that IFFT130 modulates to serial signal to carry out serial transmission at parallel-serial converter 140.Framer 150 is added in the prefix of quadrature between the subchannel to this serial signal, carries out window (windowing) preventing the inter symbol interference on it, and the transmission consequential signal.
Be sent to ONU receiver 200 from the signal of distant transmitter 100 transmission by channel 300.At this moment because each distant transmitter 100 by different transmission lines to ONU receiver 200 transmission signals, so the FEXT that sends from another adjacent transmission lines is added on the original data signal, and be sent to ONU receiver 200.
The frame device 210 that goes of ONU receiver 200 removes the prefix that is added by framer 150 that is used to keep quadrature from described signal, and they are transferred to serial-parallel converter 220.Serial-parallel converter 220 will convert parallel signal to by the data-signal that goes frame device 210 to remove prefix, and be input to FFT230, with by demodulation.
The data-signal that parallel-serial converter 260 will compensate influence converts serial signal to, and is input to projection instrument 270.Go projection instrument 270 that the complex data conversion of signals is become bit stream signal, and be included in the amplitude limiter 271 in the front portion of projection instrument 270.Amplitude limiter 271 carries out determination processing, to find from nearest original the trooping of the coordinate figure of input data signal.Deduct as original the trooping of output valve by input value and to find decision errors, and use this decision errors to determine the tap coefficient of FEXT arrester 250 from amplitude limiter 271.
In general, for DMT system transmissions data, require to carry out initialization process, described initialization process comprises starting handles (handshaking contact); Training (training) is handled; Handle with Multiple Channel Analysis and exchange.Start (handshaking contact) processing and check whether transmitter is ready to the receiver transmission signals.The training of the synchronous and equalizer that carries out code element is handled in training.The SNR (signal to noise ratio) that measures each subchannel is handled in Multiple Channel Analysis and exchange, has the bit table (bit table) that the position loads (bit loading) information with generation, and makes transmitter and receiver can exchange definite various parameters.
Training is handled and is carried out the estimation of each tap coefficient, and described tap coefficient is the transfer function of equalizer 240 and FEXT arrester 250.
See Fig. 2 and 3, the following describes the elimination FEXT method in the DMT system of first and second embodiment according to the present invention.
Fig. 2 and 3 illustrates the details of the work of the FEXT arrester in the DMT system of first and second preferred embodiments according to the present invention respectively.
For convenience of description, suppose to receive the situation of data-signal from two transmission lines that connect two distant transmitters 100 respectively, and because subchannel is independently and they are not interfering with each other, thus the subchannel value of distant transmitter 100 and ONU receiver 200 each can mate.For convenience of explanation, use single subchannel.
In the tap coefficient of estimating FEXT arrester 250, different according to the method for the elimination FEXT of first embodiment and second embodiment.In method according to the elimination FEXT of first embodiment of the invention, equalizer 240 uses different decision errors converge tap coefficient and eliminates FEXT with FEXT arrester 250, in the method according to the elimination FEXT of second embodiment of the invention, equalizer 240 uses identical decision errors to eliminate FEXT with FEXT arrester 250.
Shown in Fig. 2 and 3, by corresponding transmission line, the signal a (n) and the b (n) that transmit from distant transmitter 100 are transferred to ONU receiver 200.At this moment, transmission signals b (n) is sent to another transmission line of transmission transmission signals a (n), and becomes FEXT.
EQ (n) and FC (n) represent the transfer function of equalizer 240 and FEXT arrester 250 respectively, and described transfer function is updated up to they convergences.Cha and CHb represent the transfer function of transmission-line attenuation in the transmission line of transmission transmission signals a (n) and b (n) respectively.FX represents that the transfer function when transmission signals b (n) becomes the FEXT of transmission signals a (n), the value of above-mentioned transfer function seldom change with respect to the time.
At first, see Fig. 2, the following describes method according to the elimination FEXT of first preferred embodiment of the invention.
As shown in the DMT system, the receiver of ONU receiver 200 comprises: equalizer 241 and 242, and they are connected to from the data-signal a (n) of each distant transmitter and b (n); With FEXT arrester 251, it is connected to the output of equalizer 241, is used to eliminate the FEXT that b (n) causes. Amplitude limiter 271 and 272 is arranged on the output of equalizer 241 and 242, judges original trooping with the output valve from equalizer 241 and 242.Amplitude limiter 273 also is set, and it is used for judging original trooping from the value of having been removed FEXT by FEXT arrester 251 in the output of equalizer 241.
According to following equation 1, will be as the tap coefficient EQ of the transfer function of equalizer 241
a(n) be updated to new tap coefficient EQ
a(n+1).
Here, β is a step-length of determining the convergency factor of described equalizer 241, E
2(n) be the decision errors of equalizer 241, it be poor between the output of amplitude limiter 273 and the input value and
Be the estimated value of a (N) that makes by ONU receiver 200, i.e. the value judged of amplitude limiter 271.
To be updated to new tap coefficient FC (n+1) as the tap coefficient FC (n) of the transfer function of FEXT arrester 251 according to following equation 2.
Equation 2
Here β ' is a step-length of determining the rate of convergence of FEXT arrester 251, E
1(n) be the decision errors of the output of amplitude limiter 271 and the difference between the input value and
Be the estimated value of the b (n) that makes of ONU receiver 200, i.e. the value judged of amplitude limiter 272.
According to equation 1 and 2, each code element is upgraded the tap coefficient EQ of equalizer 241 and arrester 251
a(n) and FC (n) to converge to EQ
aAnd FC.Therefore, when the tap coefficient of enough past time and equalizer 241 and FEXT arrester 251 is restrained respectively, the FEXT that another transmission line causes is added to from the transmission signals a (n) of distant transmitter 100 transmission, to produce as expressing in the equation 3, at the signal a before equalizer 241 inputs of ONU receiver 200
1(n).
Equation 3
a
1(n)＝a(n)×CH
a+b(n)×FX
Then, equalizer 241 compensation transmission-line attenuations, therefore, a
1(n) become a shown in the equation 4
2(n)
Equation 4
a
2(n)＝a(n)×CH
a×EQ
a+b(n)×FX×EQ
a
Because produced a from the signal b (n) of another transmission line
2(n) play the FEXT of noise contributions, so with the estimated value of b (n)
Eliminate FEXT.That is, equation 5 is given in the signal a before amplitude limiter 273 inputs
3(n).
Equation 5
Because CH
aBe the transfer function of transmission-line attenuation, and EQ
aBe the transfer function of compensation transmission-line attenuation, so satisfy EQ
a=CH
a -1Because
Be the estimated value of b (n), so satisfy
And because converge to FX * EQ as the FC of the transfer function of FEXT arrester 251
aSo, satisfy FC ≈ FX * EQ
aTherefore, provide equation 5, and a that has eliminated FEXT (n) only is provided, thereby eliminate FEXT according to equation 6.
Next, eliminate the method for FEXT according to second preferred embodiment of the invention with reference to Fig. 3 explanation.
Different with first embodiment make equalizer 241 can use identical decision errors with FEXT arrester 251 according to the method for the elimination FEXT of second preferred embodiment.Therefore, do not need to find the decision errors E of equalizer 241
2(n) amplitude limiter.That is the decision errors E of equalizer 241 usefulness,
2(n) has decision content E with FEXT arrester 251 usefulness
1(n) identical value.Therefore, according to equation 7 with equalizer 241 and FEXT arrester 251 tap coefficient EQ separately
a(n) and FC (n) be updated to new tap coefficient EQ
aAnd converge to EQ (n+1) and FC (n+1),
aAnd FC.
Equation 7
As explanation in the equation 3 to 6, handle to eliminate FEXT subsequently.By on equalizer 241 and FEXT arrester 251, use identical decision errors, the tap coefficient FC of FEXT arrester 251 restrain more close FX * EQ
a
In first and second preferred embodiments, suppose to receive data-signal, and use single subchannel from the transmission line that is connected to two distant transmitters, still, the invention is not restricted to this.Those skilled in the art can understand the processing that is used to eliminate at the FEXT that produces at an easy rate when a plurality of distant transmitters receive data-signal from the above description, therefore, does not give unnecessary details at this.
According to the present invention, by the FEXT arrester is added to the DMT system, can eliminate the FEXT that adjacent transmission lines causes, therefore, improved data rate and SNR with the strengthening system performance.
Though the present invention has been described in conjunction with being considered to preferred forms, it should be understood that, the invention is not restricted to described embodiment, on the contrary, present invention resides in the various changes in the spirit and scope of claims and be equal to arrangement.
Claims (8)
1. discrete multisound system, described discrete multisound system comprises: is connected to optical network unit receiver, is used to receive the data-signal that combines from the far-end cross talk of at least one second transmission line from first transmission line of distant transmitter,
Wherein said optical network unit receiver comprises:
Equalizer, be used for using described equalizer tap coefficient, the compensation in the described transmission-line attenuation that combines the data-signal of far-end cross talk; With
The far-end cross talk arrester is used to use the decision content of the tap coefficient of described far-end cross talk arrester and the data by described second transmission line to eliminate the influence that is caused by described far-end cross talk; With
Wherein described far-end cross talk is eliminated in the output that deducts described far-end cross talk arrester by the output from described equalizer.
2. discrete multisound system according to claim 1, the tap coefficient of wherein said far-end cross talk arrester restrain by the decision content of the decision errors of the factor of the rate of convergence of determining described far-end cross talk arrester, described optical network unit receiver and the data by described second transmission line and
The tap coefficient of described equalizer is by the decision errors of the factor of the rate of convergence of determining described equalizer, described equalizer and the decision content convergence of described optical network unit receiver.
3. discrete multisound system according to claim 1, the tap coefficient of wherein said far-end cross talk arrester restrain by the decision content of the factor of the rate of convergence of determining described far-end cross talk arrester, decision errors on described optical network unit receiver and the data by described second transmission line and
The tap coefficient of described equalizer is by the decision errors of the factor of the rate of convergence of determining described equalizer, described optical network unit receiver and the decision content convergence of described optical network unit receiver.
4. discrete multisound system, described discrete multisound system comprises: at least one first optical network unit receiver, it is connected to first transmission line from least one distant transmitter; The second optical network unit receiver, it is connected to second transmission line different with described first transmission line, is used to receive the data-signal that combines from the far-end cross talk of described first transmission line,
The wherein said first optical network unit receiver comprises:
First equalizer is used for compensating the transmission-line attenuation of the data-signal that receives by described first transmission line; With
First amplitude limiter, be used for output to described first equalizer make a determination with find decision content and
The described second optical network unit receiver comprises:
Second equalizer is used for using the tap coefficient compensation of described second equalizer to combine the transmission-line attenuation of the data-signal of far-end cross talk; With
The far-end cross talk arrester is used to use the tap coefficient of described far-end cross talk arrester and the decision content of the described first optical network unit receiver, with calculate the influence that causes by described far-end cross talk and
Described far-end cross talk is eliminated in the output that cuts described far-end cross talk arrester by the output from described second equalizer.
5. discrete multisound system according to claim 4, also comprise second amplitude limiter, be used for that the output from described second equalizer is cut the value that the output of described far-end cross talk arrester obtains and make a determination, to find the decision content of the described second optical network unit receiver.
6. discrete multisound system according to claim 5, the tap coefficient of wherein said far-end cross talk arrester is by the decision errors of the factor of the convergency factor of determining described far-end cross talk arrester, the described second optical network unit receiver and the decision content convergence of the described first optical network unit receiver.
7. discrete multisound system according to claim 6 wherein upgrades the described tap coefficient of described far-end cross talk arrester continuously by following formula, to converge to predetermined value:
Here FC (n) is the tap coefficient of described far-end cross talk arrester, and β is the factor of determining the convergency factor of described far-end cross talk arrester, E
1(n) be the described second optical network unit receiver decision errors and
It is the decision content of the described first optical network unit receiver.
8. discrete multisound system according to claim 6, the tap coefficient of wherein said second equalizer is by the decision errors of the factor of the convergency factor of determining described second equalizer, the described second optical network unit receiver and the decision content convergence of the described second optical network unit receiver.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2002-0018271A KR100465640B1 (en) | 2002-04-03 | 2002-04-03 | Dmt system for reducing far end crosstalk |
| KR2002/18271 | 2002-04-03 |
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| Publication Number | Publication Date |
|---|---|
| CN1507716A CN1507716A (en) | 2004-06-23 |
| CN1307816C true CN1307816C (en) | 2007-03-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB028095405A Expired - Lifetime CN1307816C (en) | 2002-04-03 | 2002-04-30 | DMT system for reducing far end crosstalk |
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| Country | Link |
|---|---|
| JP (1) | JP2005520450A (en) |
| KR (1) | KR100465640B1 (en) |
| CN (1) | CN1307816C (en) |
| AU (1) | AU2002304175A1 (en) |
| WO (1) | WO2003084117A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7570685B2 (en) * | 2003-10-06 | 2009-08-04 | Hiroshi Takatori | System, method and apparatus for crosstalk cancellation |
| EP1920544B1 (en) * | 2005-09-02 | 2016-08-24 | Ofidium Pty Ltd | Methods and apparatus for optical transmission of digital signals |
| CN100442724C (en) * | 2005-09-16 | 2008-12-10 | 华为技术有限公司 | Method and apparatus for crosstalk testing of multi-user communication line |
| JP4835293B2 (en) | 2006-07-13 | 2011-12-14 | 日本電気株式会社 | Transmission output control device, multi-carrier transmission system, transmission output control method, and transmission output control program |
| US8357013B2 (en) * | 2009-01-22 | 2013-01-22 | Hirose Electric Co., Ltd. | Reducing far-end crosstalk in electrical connectors |
| US8576690B2 (en) * | 2010-03-23 | 2013-11-05 | Ikanos Communications, Inc. | Systems and methods for implementing a multi-sensor receiver in a DSM3 environment |
| US8559547B2 (en) * | 2010-10-01 | 2013-10-15 | Alcatel Lucent | Channel estimation utilizing control signals transmitted by an activating line during initialization |
| CN110798303B (en) * | 2013-05-05 | 2022-08-05 | 领特贝特林共有限责任两合公司 | Time sharing for low power modes |
| KR200489531Y1 (en) | 2018-12-06 | 2019-07-01 | 제희광 | A frame use to connecting duplex type panel |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5285474A (en) * | 1992-06-12 | 1994-02-08 | The Board Of Trustees Of The Leland Stanford, Junior University | Method for equalizing a multicarrier signal in a multicarrier communication system |
| EP0828363A2 (en) * | 1996-09-04 | 1998-03-11 | Texas Instruments Incorporated | Multicode modem with a plurality of analogue front ends |
| EP0987830A1 (en) * | 1998-04-10 | 2000-03-22 | Mitsubishi Denki Kabushiki Kaisha | Digital communication device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6097763A (en) * | 1997-10-31 | 2000-08-01 | Pairgain Technologies, Inc. | MMSE equalizers for DMT systems with cross talk |
| JP3480313B2 (en) * | 1998-05-26 | 2003-12-15 | 富士通株式会社 | Digital subscriber line transmission method and xDSL device |
| AU1759801A (en) * | 1999-11-11 | 2001-06-06 | Voyan Technology | Method and apparatus for mitigation of disturbers in communication systems |
| EP1109329B1 (en) * | 1999-12-14 | 2003-04-02 | STMicroelectronics S.A. | DSL transmission system with far-end crosstalk cancellation |
| US6628704B1 (en) * | 2000-02-29 | 2003-09-30 | Centillium Communications, Inc. | Equalizer training for ADSL transceivers under TCM-ISDN crosstalk environment |
-
2002
- 2002-04-03 KR KR10-2002-0018271A patent/KR100465640B1/en not_active IP Right Cessation
- 2002-04-30 JP JP2003581397A patent/JP2005520450A/en active Pending
- 2002-04-30 WO PCT/KR2002/000803 patent/WO2003084117A1/en active Application Filing
- 2002-04-30 AU AU2002304175A patent/AU2002304175A1/en not_active Abandoned
- 2002-04-30 CN CNB028095405A patent/CN1307816C/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5285474A (en) * | 1992-06-12 | 1994-02-08 | The Board Of Trustees Of The Leland Stanford, Junior University | Method for equalizing a multicarrier signal in a multicarrier communication system |
| EP0828363A2 (en) * | 1996-09-04 | 1998-03-11 | Texas Instruments Incorporated | Multicode modem with a plurality of analogue front ends |
| EP0987830A1 (en) * | 1998-04-10 | 2000-03-22 | Mitsubishi Denki Kabushiki Kaisha | Digital communication device |
Non-Patent Citations (1)
| Title |
|---|
| PERFORMANCE EVALUATION OF A FAST COMPUTATION ALGORITHM FORTHE DMT IN HIGH-SPEED SUBSCRIBER LOOP INKYU LEE,ET AL,IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS,Vol.13 No.9 1995 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1507716A (en) | 2004-06-23 |
| JP2005520450A (en) | 2005-07-07 |
| AU2002304175A1 (en) | 2003-10-13 |
| WO2003084117A1 (en) | 2003-10-09 |
| KR100465640B1 (en) | 2005-01-13 |
| KR20030079314A (en) | 2003-10-10 |
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